Molecular diagnostic assay system

Abstract

Improved sub-assemblies and methods of control for use in a diagnostic assay system adapted to receive an assay cartridge are provided herein. Such sub-assemblies include: a brushless DC motor, a door opening/closing mechanism and cartridge loading mechanism, a syringe and valve drive mechanism assembly, a sonication horn, a thermal control device and optical detection/excitation device. Such systems can further include a communications unit configured to wirelessly communicate with a mobile device of a user so as to receive a user input relating to functionality of the system with respect to an assay cartridge received therein and relaying a diagnostic result relating to the assay cartridge to the mobile device.

What is claimed is: 
     
       1. A door opening system for a diagnostic assay system comprising:
 a chassis of the diagnostic assay system; 
 a brushless DC (BLDC) motor coupled to the chassis of the diagnostic assay system; 
 a back drivable transmission operable by the BLDC motor between a top-end and a bottom-end travel position of the back drivable transmission; 
 a door movable relative to the chassis of the diagnostic assay system between a closed position and an open position, wherein the door is actuatable between the open and closed position by the BLDC motor through the back drivable transmission, wherein the top-end travel position of the back drivable transmission corresponds to the open position of the door and the bottom-end travel position corresponds to the closed position of the door; 
 a cartridge loader configured to engage and intake a sample cartridge within the diagnostic system, wherein the cartridge loader is operably coupled to the BLDC motor through the back drivable transmission; 
 driver circuitry configured to:
 operate the back drivable transmission based on a current measurement of the BLDC motor by a current sensor, the current measurement being associated with back-driving events against the back drivable transmission at the top-end and bottom-end travel positions; 
 detect a first back-driving event occurring against the back drivable transmission at the top-end or bottom-end travel positions by monitoring the current measurement of the BLDC motor; 
 based on detecting the first back-driving event, cease operation of the BLDC motor to place the door in the open position, and place the cartridge loader into position to engage and intake the sample cartridge within the diagnostic system. 
 
 
     
     
       2. The system of  claim 1 , wherein the back drivable transmission comprises a lead screw driven by the BLDC motor, wherein the lead screw is back-drivable. 
     
     
       3. The system of  claim 2 , wherein a bridge is threaded to the lead screw. 
     
     
       4. The system of  claim 3 , wherein a first and a second elongated rack portion are connected to the bridge. 
     
     
       5. The system of  claim 4 , wherein the first and second elongated rack portions are both moveable between the top and the bottom end travel positions. 
     
     
       6. The system of  claim 5 , wherein the first and second elongated rack portions respectively include first and second racks. 
     
     
       7. The system of  claim 6 , wherein the first and second elongated rack portions further respectively include first and second cam pathways. 
     
     
       8. The system of  claim 7 , wherein the first and second cam pathways are moveably coupled to cam followers of first and second cartridge loading arms. 
     
     
       9. The system of  claim 5 , further comprising first and second pinion gears respectively engaged with the first and second rack portions. 
     
     
       10. The system of  claim 9 , further comprising first and second door gears respectively driven by the first and second pinions. 
     
     
       11. The system of  claim 10 , wherein the door includes first and second door racks respectively engaged with the first and second gears. 
     
     
       12. The system of  claim 1 , wherein the BLDC motor does not include any encoder hardware and the back drivable transmission does not include any position sensors. 
     
     
       13. The system of  claim 1 , wherein the back drivable transmission is coupled to a cartridge loader, and wherein force applied to the cartridge loader by a cartridge inserted into the door back drives the back drivable transmission, said force being detected as a torque applied to the back drivable transmission. 
     
     
       14. A method for operating a door opening system for a diagnostic assay system comprising:
 receiving a command to open a cartridge receiving door of the diagnostic assay system that is configured for accepting a sample cartridge to perform diagnostic assays; 
 operating a brushless DC (BLDC) motor coupled to a back drivable transmission to open the door from a closed position with a driver circuitry of the BLDC motor, the back drivable transmission being operationally coupled to the door and a cartridge loader configured to engage and intake a sample cartridge within the diagnostic system; 
 detecting a first back-driving event occurring against the back drivable transmission by monitoring a current of the BLDC motor sensed by a current sensor in the driver circuitry; 
 based on detecting the first back-driving event, ceasing operation of the BLDC motor that places or maintains the door in an open position, and placing the cartridge loader into position to engage and intake the sample cartridge within the diagnostic system. 
 
     
     
       15. The method of  claim 14 , wherein the BLDC motor does not include any encoder hardware and the back drivable transmission does not include any position sensors. 
     
     
       16. The method of  claim 14 , wherein the first back driving event comprises an aspect of the back drivable transmission hitting a travel limit. 
     
     
       17. The method of  claim 14 , wherein the back drivable transmission comprises a lead screw. 
     
     
       18. The method of  claim 14 , further comprising detecting a second back driving event occurring against the back drivable transmission while the door is in the open position. 
     
     
       19. The method of  claim 18 , wherein the second back driving event is caused by a cartridge body being pushed against of the cartridge loader. 
     
     
       20. The method of  claim 19 , further comprising based on detecting the second back driving event, operating the BLDC motor to place the door back into the closed position. 
     
     
       21. The method of  claim 20 , further comprising detecting a third back driving event occurring against the back drivable transmission. 
     
     
       22. The method of  claim 20 , based on detecting the third back-driving event, ceasing operation of the BLDC motor to place the door in a closed position.